docs: def latexpdf():
      """make LaTeX files and run them through pdflatex"""
      rc = latex()
      print('Running LaTeX files through pdflatex...')
      builddir = os.path.join(BUILDDIR, 'latex')
      subprocess.call(['make', '-C', builddir, 'all-pdf'])
      print('pdflatex finished; the PDF files are in {}.'.format(builddir))